Means for shifting the axis of boom means or the like



July 30, 1963 J. D. CLARK 3,099,358

MEANS FOR SHIFTING THE AXIS OF BOOM MEANS OR THE LIKE Filed Aug. 1, 196056 V 7 541% 1 MGM Unite States ate This invention concerns structureshaving booms or .the like for lifting or carrying loads, for instance,or to which other structure is attached for various purposes. Theinvention especially pertains to excavation equipment, such as backhoes.

A primary object of the invention is to provide a structure having boommeans or the like in which the axis of horizontal swinging movement ofthe boom means is laterally shiftable, as for instance in the case ofbackhoes to permit digging along walls, foundations, or the like as wellas in the ordinary centered position of the boom means.

Another object is to provide for the above shitting of the axis of thehorizontal swinging movement without dismantling or disconnecting heavyboom means and any attached structure from the supporting structure ofthe same, moving the same to the side, and remounting it, with all theattendant difliculty, time, and great efliort involved in such a majoroperation.

Another object of the invention is to provide a structure havinghorizontally swingable boom means or the like and means for effectinghorizontal swinging movement of the boom means, in which the axis of thehorizontal swinging movement of the boom means is laterally shiftableand the means for effecting the swinging movement of the boom means isalso effective to produce the shifting of the axis.

Another object is to provide a structure having boom means or the likein which the YELXI'JS of horizontal swinging movement of the boom meansis laterally shiftable under the action of the means normally Producingthe swinging movement of the boom means and further, in which the boommeans is automatically retained at least substantially parallel to theposition thereof prior to shifting of the axis during and uponcompletion of the shifting movement of the axis, so as to eliminate atleast any major adjustment of the boom means in the case of a backhoe,when the boom means and attached structure thereof are in an unturned,straight rearward position prior to the shifting of the axis, in orderto dig along walls, foundations, or the like parallel thereto andparallel to the longitudinal axis of the vehicle on which the backhoe ismounted and to the [direction of movement of the vehicle along the wallor the like.

Another object is to provide a structure having boom means or the likein which the axis of horizontal swinging movement of the boom means islaterally shiftable, such shifting of the axis being effected in anexceptionally fast and effortless manner.

Another object is to provide a structure having boom means or the likein which the axis of horizontal swinging movement of the boom means islaterally shiftable merely by removing pin means, operating the meansfor normally swinging the boom means about its axis, and repinning theboom means in that position.

Another object is to provide a structure having boom means or the likein which the axis of horizontal swinging movement of the boom means islaterally shiftable and the operation of means for effecting theswinging movement of the boom means about its axis is unafiected by theshifting of the axis and remains fully operative in any shifted positionthereof.

Another object is to provide a structure :as above set 2 forth which isof very simple and inexpensive construction.

Other objects, advantages, and features of the invention will beapparent from the following illustrative description, when read inconjunction with the accompanying drawing in which:

FIGURE 1 is a fragmentary sectional view of a backhoe constructed inaccordance with a. preferred form of the invention and taken on line 11of FIGURE 2; and

FIGURE 2 is a fragmentary sectional view of the same taken on line 2-2of FIGURE 1.

Referring to the drawing figures in detail, the reference numeral 1designates a wheeled tractor having a pair of side rails 7 suitablyattached thereto. A transversely extending vertical plate 9 is attachedto the rear ends of each of the rails 7 by means of cars 10 welded tothe plate and connected to the rails 7 by bolts. Diagonal supportmembers 12, only one of which is shown in the drawing, extend from thetop of the plate 9 on each side thereof to each of the rails 7,respectively, to complete the support of the plate on the tractor.

Upper and lower, spaced, parallel members 15 and 16 are suitably securedto the plate 9 at the top and bottom thereof by welding. These membersare of identical outer contour which is substantially semi-circular ordome shaped. The upper member 15 is a solid plate while the lower member16 is of open construction consisting of a generally semicircular ordome shaped portion 17 and a crossplate 18 extending between the sidesthereof at the front and attached thereto by welding. A plurality ofarcuately arranged holes 20 are positioned along the rear periphery ofeach of the members 15 and 16, the holes in each member havingcorresponding holes in the other member which are in vertical alignmentor coaxial relation therewith. The purpose of these holes will bebrought out hereinafter.

Mounted on the upper plate member 15 is a control cab 22 including thecontrols 23 for operating'the backhoe. Vertically extending plates 21are joined to the members 15' and 16 at top and bottom by welding forfurther support of the latter members in their spaced- .apart parallelrelation. Laterally extending stabilizers 26 including their pads 27(only one of which is shown) are pivotally connected to joined plates 21and 9 for the customary function, being operated by the usual cylinders28 also connected to the plates 21, respectively. A dome shaped shroudor enclosing sheet 29 extends between the spaced members 15 and 16 andthe side plates 21 being suitably joined thereto as by welding and beingslot-ted at 30 and 31 for a purpose which will become apparent below.The structure thus far described principally constitutes support meansfor the remaining portions of of the backhoe.

Upper and lower block members 32 having rearwardly extending, spacedears 33- are secured to the plate 9 by welding. A link member generallydesignated 34 is connected between the ears 33 of the upper and lowerblock members 3-2 by means of pivot elements 37 for horizontal swingingmovement about the vertical axis through the elements 37. Removable pins39 are received within the center holes 20 in the upper and lowermembers 15 and 16 of the supporting structure, extending through theupper and lower arms 40 of the link member 34 to retain the lattermember in a centered or neutral position, shown in full lines in FIGURE1 for normal use of the backhoe.

Boom means generally designated 45 is supported on the link member 34for horizontal swinging movement. More particularly, this connection ismade between the swing tower portion 46 of the boom means and the linkmember 34, the former portion having upper and lower lugs 47 receivedbetween upper and lower sets of spaced ears 48, respectively, of thelink member '34 and pivotally connected thereto by means of verticallyextending coaial pivot elements 50. The boom 80 of the boom means isconnected to the swing tower portion 46 for vertical swinging movementby means of a horizon-tally extending pivot element 51 extending throughthe members. A hydraulic cylinder 53 is pivotally connected between theswing tower 46 and a portion of the boom 80 (not shown) for operatingthe boom about the horizontal pivot in accordance with present practice.A dip stick (not shown) is pivotally connected to the rear end of theboom 80 and a digging bucket (also not shown) is pivotally connected tothe dip stick and hydraulic cylinders (also not shown) appropriatelyconnected for operating the dip stick and bucket.

A sprocket 56 is fixedly attached to the swing tower 46 by being keyedto the lower pivot element 50 which is in turn keyed to the swing tower46. The element 59 is freely rotatable within the lower ears 48 of thelink member 34 in order to provide for the horizontal swinging movementof the boom means relative thereto.

Thus, any torque applied to the periphery of sprocket 56 effectsrelative movement between swing tower 46 and link member 34. As isevident from well-known operating characteristics of backhoes andanalogous equipment, in which the mass of the boom assembly (e.g. theboom, dipper stick, bucket, and actuating components) is large withrespect to the mass of link member 34, if link member 34 is free to turnabout both its pivotal connections as the described relative movement iseiiected (that is, with locking pins 39 removed), then the efiect willbe angular displacement of link member 34 and a substantial transversedisplacement of the boom assembly, for example, as indicated by thedisplacement of boom 50 from the solid line position to the dash-dotline position in FIGURE 1. Alternatively, when the locking pins 39 areinserted in position as shown in FIGURE 2, then the effect of therelative movement between the swing tower and the link member 34 is totranslate this motion into angular displacement of the swing tower andthe attached boom assembly, thereby eflecting angular displacement ofthe boom assembly.

Horizontally spaced, coplanar block members 59 are attached to the plate9 by welding. Single acting hydraulic cylinders 60 and 61 are pivotallyconnected to the blocks 59 for horizontal swinging movement by means ofthe vertical pivot elements 64. The piston rods 65 of the cylinders 60and 61 are suitably attached to: a flexible linked chain 67 extendingaround and engaging the teeth of a portion of the sprocket 56 as shown.

As previously pointed out, for normal operation of the backhoe the linkmember 34 is in the centered full line position shown in FIGURE 1. Forswinging the boom means 45 and the attached linkage or gear horizontallyto the right or left as seen in FIGURE 1, the hydraulic cylinders 60 and61 are actuated, respectively. During actuation of each of the cylinderswhich pulls the respective ends of the flexible chain 67', the other ofthe cylinders, which is not being actuated, is connected to sump toallow the cylinder to be freely extended by the pulling force of theflexible chain unharnpered.

Should it be desired to dig a trench or otherwise excavate along afoundation or wall of a building for instance, the boom means 45 andattached linkage is very easily positioned for such excavation. Inaccordance with the present invention the upper and lower pins 39*extending between the upper and lower spaced members 15 and 16 of thesupport structure and the link member 34- and which may be retained inposition merely by gravity are simply slipped out of their holes and oneor the other of the cylinders 60 and 61 actuated for the shifting actionin the desired direction. FIGURE 1 includes a phantom line showing ofthe movable parts of the backhoe in a shifted position to the right forexcavating along a foundation or a wall on the right thereof. Thestabilizer 26 on the side to which the boom means and attached linkageis shifted should also be raised out of the way so as not to be anobstruction. Upon shifting of the movable parts, the pins 35 are droppedthrough the holes 20 corresponding to the new position and through thearms 43 to secure the link member 34 and other parts in the shiftedposition during operation of the backhoe in the normal fashion. Thebackhoe can be shifted from the righthand position back to the centerposition or to the other side by again removing the pins 39 andactuating the proper cylinder until the desired position is achieved, atwhich time the pins 39 are again dropped through the proper holes 20 andarms 40'.

It should be evident that the same actuating means, the hydrauliccylinders 60 and 61, are used for swinging the boom means 45 andattached linkage horizontally during normal operation of the excavatingdevice and also to shift the same to the right or left for the diggingalong foundations, walls, or the like. The shifting movement is ofcourse produced by operating the proper cylinder with the pins 39removed which produces a double pivoting about the fixed pivot at '37and swinging pivot at 50 in opposite directions about the two pivotpoints respectively. By the use of the construction shown with thesprocket 56 or other circular or oppositely disposed arcuate means andflexible force transmittable means as the chain 67, the angular pivotalmovement about the two pivot points at 37 and 50 is approximately equal,to thus automatically substantially retain the boom means 45 andattached linkage in parallel relation to the longitudinal axis of thevehicle 1 and supporting structure mounted thereon when the boom meansand attached linkage are in the straight rearwardly extending positionshown in full lines in FIGURE 1 prior to the shifting. This automaticsubstantially parallel relation which is maintained during the shiftingmovement and had at the end thereof eliminates the need of any majorspecial adjustment in order to place the boom means 45 and attachedlinkage in such a parallel relation with the axis of the vehicle inorder to dig parallel thereto and to the wall or foundation.

Additional holes 20' may be provided in the upper and lower spacedmembers 15 and 16 of the supporting structure for pinning the linkmember 34 in any desired position intermediate the neutral or straightrearwardly extending position and the extreme righthand and lefthandpositions.

It is pointed out that the actuating cylinders 60' and 61 are fullyeffective in any swung or shifted position, after pinning by means ofthe pins 39, and without any alteration or adjustment of any sort tooperate the boom means 45 and attached linkage in horizontal movement,if desired.

It is therefore seen that the present invention provides a very rapid,simple, and inexpensive way of shifting the vertical pivot point of theboom means or the like in which time consuming, difficult and mostdistasteful and expensive disconnection and remounting of the boom meanson the supporting structure is eliminated, such shifting being effectedby the ordinary means for swinging the boom means and also automaticallysubstantially preserving the relation of the boom means and attachedlinkage parallel to the longitudinal axis of the vehicle and supportingmeans without need of additional adjustment.

Although a single illustrative form has been described and shown in thedrawing, it is not desired to be limited to this construction in theappended claims inasmuch as other forms and modifications may be had.For instance, although a circular sprocket 56 has been shown anddescribed, arcuate portions can be fixedly supported on opposite sidesof the boom means or of the center line thereof, being supportedinwardly of the side surfaces, with the axis of both arcuate portionsbeing the axis of the pivot pins 5t) and separate lengths of flexiblechain or cable connected between each of the cylinders 60 and 61 orother suitable actuating means and the respective arcuate portionstowards the rear thereof instead of having the flexible lengths joinedat the rear as they are in the disclosed form and extending around acompletely circular sprocket member. The arcuate portions also need notnecessarily be in a single plane.

Although the detailed description has been a backhoe construction, theinvention may be applied to any similar excavating device or otherconstruction employing a boom whether vertically pivotable or not orother constructions having an elongated swingable member.

It is also pointed out and it should be clearly under stood that suchterms as horizontal, vertical and the like appearing in thespecification and also the appended claims are merely convenient termsrelative to the horizontal or level position of the vehicle andsupporting structure shown in the drawing and are not to be taken in anabsolute sense so as to limit certain structure in the claims to ahorizontal or vertical disposition. This is believed obvious inasmuch asthe vehicle 1, for instance, to which the backhoe device, for instance,is mounted can be and usually is on ground which is not level or even ifit should be level the stabilizers 26 on each side thereof may beadjusted by means of their operating hydraulic cylinders so as toproduce a variance from a level position.

The appended claims should therefore be interpreted only by their termsconstrued in the broad overall spirit of the present invention in itsvarious aspects.

What is claimed is:

1. A control arrangement for displacing a driven element from an initialposition relative to a support structure, said structure defining areference pivot axis, comprising: a first link member, having a masssmall with respect to the mass of said driven element, coupled to saidsupport structure along said reference pivot axis; a second link member,coupled to said driven element, and coupled to said first link memberalong an intermediate pivot axis displaced from said reference pivotaxis; means for effecting relative displacement of said first and secondlink members; and locking means for selectively restraining said firstlink member against movement, operable in a first position to translatesaid relative displacement into rotation of said driven element, andoperable in a second position to translate said relative displacementinto transverse displacement of said driven element.

2. A control arrangement for displacing a driven element from an initialposition relative to a support structure, said structure defining areference pivot axis, comprising: a first link member, having a masssmall with respect to the mass of said driven element, pivotally coupledto said support structure along said reference pivot axis; a second linkmember, coupled to said driven element; means including a pivot elementfor intercoupling said second link member with said first link memberalong an intermediate pivot axis displaced from said reference pivotaxis, said pivot element being keyed to said second link member forconcomitant angular displacement therewith; means for effecting rotationof said pivot element and thereby effecting relative displacement ofsaid first and second link members; and locking means for selectivelyrestraining said first link member against movement, operable in a firstposition to translate said relative displacement into rotation of saiddriven element, and operable in a second position to translate saidrelative displacement into transverse displacement of said drivenelement.

3. A control arrangement for displacing a driven element from an initialposition relative to a support structure, said structure defining areference pivot axis, comprising: a first link member, having a masssmall with respect to the mass of said driven element, pivotally coupledto said support structure along said reference pivot axis; a second linkmember, coupled to said driven element; means, including a pivot elementkeyed to said second link member, for coupling said first link memberWith said second link member along an intermediate pivot axis displacedfrom said reference pivot axis; means for imparting rotation to saidpivot element to effect relative displacement of said first and secondlink members, including a first and a second hydraulic unit aflixed tosaid support structure and selectively operable to regulate thedirection and extent of said rotation; and locking means for selectivelyrestraining said first link member against movement, operable in a firstposition to translate said relative displacement into rotation of saiddriven element, and operable in a second position to translate saidrelative displacement into transverse displacement of said drivenelement.

4. A control arrangement for displacing a boom assembly from an initialposition relative to a support structure, said structure defining areference pivot axis, comprising: a first link member, having a masssmall with respect to the mass of said boom assembly, coupled to saidsupport structure along said reference pivot axis; a second link member,coupled at one end to said boom assembly, and coupled at the other endto said first link member along an intermediate pivot axis displacedfrom said reference pivot axis; motion-transmitting means, including atleast one selectively operable hydraulic actuator, coupled between saidsupport structure and said second link member, and selectively operableto effect relative displacement of said first and second link members;and locking means, operable in a first position to secure said firstlink member in position with respect to said support structure andthereby translate said relative movement into rotation of said secondlink member about said intermediate pivot axis to rotate the boomassembly to a displaced position which is angularly related to saidinitial position, and operable in a second position to enable rotationof said first link member about both said reference pivot axis and saidintermediate pivot axis, thereby translating said relative movement intorotation of said first link member about said reference pivot axis assaid boom assembly is displaced transversely to a second positionsubstantially parallel to said initial position.

5. A control arrangement for displacing a driven element relative to asupport structure, comprising: a first link member, having a mass smallWith respect to the mass of said driven element, pivotally coupled tosaid support structure; a second link member, coupled to said drivenelement, and pivotally coupled to said first link member; means foreffecting relative displacement of said first and second link members;and locking means for selectively restraining said first link memberagainst movement.

6. A control arrangement for a backhoe unit for displacing the boomassembly from an initial position with respect to the backhoe supportstructure, said support structure defining a reference pivot axis and aplurality of spaced-apart locking apertures, comprising: a link member,having a mass small with respect to the mass of the boom assembly anddefining a reference aperture therein pivotally coupled to said supportstructure along said reference pivot axis; a swing tower, coupled tosaid boom assembly; means, including at least one pivot element keyed tosaid swing tower, for coupling said swing tower to said link memberalong an intermediate pivot axis displaced from said reference pivotaxis; motion-transmitting means for effecting angular displacement ofsaid pivot element and thereby effecting relative displacement betweensaid swing tower and link member; and locking means, including a pinselectively insertable through said reference aperture into one of saidlocking apertures, for selectively restraining said link member againstmovement with respect to said support structure, thus to transslate saidrelative displacement int-o rotation of the boom assembly when said pinis in the locking position, and to translate said relative displacementinto transverse movement of the boom assembly when the locking pin isremoved from said IaPent'ures.

7. A control arrangement as set forth in claim 6 and and effect thedesired relative displacement between the in which saidmotion-transmitting means comprises an swing tower and the link member.aircu-ate element alfixed to said pivot element, a. pair of hydrauliccontrol units each having a base portion afiixed References Cited in thefile of this patent to said supp0rt structure and a selectivelyextensible 5 UNITED STATES PATENTS cyhndemcal portion, and la flexiblelink coupled at one I end to one of said cylindrical portions andextending over 2,505,107 f May 1950 and in engagement with said arcuatemember and con- 26745OO Hukan 9 nected at its other end to the other ofsaid cylindrical oi-- 2834480 PTZYbYISQ May 1958 tions, wherebyoperation of one of said hydraulic units 10 effects displacement of saidflexible link and of said FOREIGN PATENTS 'arcuate element, thereby todisplace said pivot element 1,014,229 France May 28, 1952

1. A CONTROL ARRANGEMENT FOR DISPLACING A DRIVEN ELEMENT FROM AN INITIALPOSITION RELATIVE TO A SUPPORT STRUCTURE, SAID STRUCTURE DEFINING AREFERENCE PIVOT AXIS, COMPRISING: A FIRST LINK MEMBER, HAVING A MASSSMALL WITH RESPECT TO THE MASS OF SAID DRIVEN ELEMENT, COUPLED TO SAIDSUPPORT STRUCTURE ALONG SAID REFERENCE PIVOT AXIS; A SECOND LINK MEMBER,COUPLED TO SAID DRIVEN ELEMENT, AND COUPLED TO SAID FIRST LINK MEMBERALONG AN INTERMEDIATE PIVOT AXIS DISPLACED FROM SAID REFERENCE PIVOTAXIS; MEANS FOR EFFECTING RELATIVE DISPLACEMENT OF SAID FIRST AND SECONDLINK MEMBERS; AND LOCKING MEANS FOR SELECTIVELY RESTRAINING SAID FIRSTLINK MEMBER AGAINST MOVEMENT, OPERABLE IN A FIRST POSITION TO TRANSLATESAID RELATIVE DISPLACEMENT INTO